Case studies of computational simulations of fatigue crack propagation using finite elements analysis tools

This paper presents three case studies based on the numerical determination of the stress intensity factor (K) related with different crack front geometries due to fatigue using two commercial finite element analysis codes (ZENCRACK® and ABAQUS®). Cases 1 and 2 considered a double-U notch specimen used in high temperature fatigue testing. Stress distribution in the vicinity of the U notch has been obtained, as well as numeric solutions of K for crack front geometries with rectilinear, corner and unconventional crack front shapes. In the case of the standard crack geometries the results have been validated with classic solutions existing in literature. In the third case study, several computational simulations were carried out aiming at determining the K solution for distinct crack front positions, considering the influence of different geometric features of the specimen. Additionally, a stress triaxility parameter was used in order to confirm the stress state condition in the crack propagation region. The conclusions of this study are encouraging concerning the possibility of using ZENCRACK® as an advantageous computational tool for obtaining K solutions in the case of particular crack front geometries as obtained from fatigue experimental testing.